<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>CPAN::Meta::Merge - Merging CPAN Meta fragments - Perldoc Browser</title>
    <link rel="search" href="https://perldoc.perl.org/opensearch.xml" type="application/opensearchdescription+xml" title="Perldoc Browser">
    <link rel="canonical" href="https://perldoc.perl.org/CPAN::Meta::Merge">
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/styles/stackoverflow-light.min.css" integrity="sha512-cG1IdFxqipi3gqLmksLtuk13C+hBa57a6zpWxMeoY3Q9O6ooFxq50DayCdm0QrDgZjMUn23z/0PMZlgft7Yp5Q==" crossorigin="anonymous" />
    <style>
      body {
        background: #f4f4f5;
        color: #020202;
      }
      .navbar-dark {
        background-image: -webkit-linear-gradient(top, #005f85 0, #002e49 100%);
        background-image: -o-linear-gradient(top, #005f85 0, #002e49 100%);
        background-image: linear-gradient(to bottom, #005f85 0, #002e49 100%);
        filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff005f85', endColorstr='#ff002e49', GradientType=0);
        background-repeat: repeat-x;
      }
      .navbar-dark .navbar-nav .nav-link,
      .navbar-dark .navbar-nav .nav-link:focus { color: #fff }
      .navbar-dark .navbar-nav .nav-link:hover { color: #ffef68 }
      #wrapperlicious {
        margin: 0 auto;
        font: 0.9em 'Helvetica Neue', Helvetica, sans-serif;
        font-weight: normal;
        line-height: 1.5em;
        margin: 0;
        padding: 0;
      }
      #wrapperlicious h1 { font-size: 1.5em }
      #wrapperlicious h2 { font-size: 1.3em }
      #wrapperlicious h3 { font-size: 1.1em }
      #wrapperlicious h4 { font-size: 0.9em }
      #wrapperlicious h1, #wrapperlicious h2, #wrapperlicious h3,
      #wrapperlicious h4, #wrapperlicious dt {
        color: #020202;
        margin-top: 1em;
        margin-bottom: 1em;
        position: relative;
        font-weight: bold;
      }
      #wrapperlicious a { color: inherit; text-decoration: underline }
      #wrapperlicious #toc { text-decoration: none }
      #wrapperlicious a:hover { color: #2a2a2a }
      #wrapperlicious a img { border: 0 }
      #wrapperlicious :not(pre) > code {
        color: inherit;
        background-color: rgba(0, 0, 0, 0.04);
        border-radius: 3px;
        font: 0.9em Consolas, Menlo, Monaco, monospace;
        padding: 0.3em;
      }
      #wrapperlicious dd {
        margin: 0;
        margin-left: 2em;
      }
      #wrapperlicious dt {
        color: #2a2a2a;
        font-weight: bold;
        margin-left: 0.9em;
      }
      #wrapperlicious p {
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious li > p {
        margin-bottom: 0;
        margin-top: 0;
      }
      #wrapperlicious pre {
        border: 1px solid #c1c1c1;
        border-radius: 3px;
        font: 100% Consolas, Menlo, Monaco, monospace;
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious pre > code {
        display: block;
        background-color: #f6f6f6;
        font: 0.9em Consolas, Menlo, Monaco, monospace;
        line-height: 1.5em;
        text-align: left;
        white-space: pre;
        padding: 1em;
      }
      #wrapperlicious dl, #wrapperlicious ol, #wrapperlicious ul {
        margin-bottom: 1em;
        margin-top: 1em;
      }
      #wrapperlicious ul {
        list-style-type: square;
      }
      #wrapperlicious ul ul {
        margin-bottom: 0px;
        margin-top: 0px;
      }
      #footer {
        font-size: 0.8em;
        padding-top: 0.5em;
        text-align: center;
      }
      #more {
        display: inline;
        font-size: 0.8em;
      }
      #perldocdiv {
        background-color: #fff;
        border: 1px solid #c1c1c1;
        border-bottom-left-radius: 5px;
        border-bottom-right-radius: 5px;
        margin-left: auto;
        margin-right: auto;
        padding: 3em;
        padding-top: 1em;
        max-width: 960px;
      }
      #moduleversion { float: right }
      #wrapperlicious .leading-notice {
        font-style: italic;
        padding-left: 1em;
        margin-top: 1em;
        margin-bottom: 1em;
      }
      #wrapperlicious .permalink {
        display: none;
        left: -0.75em;
        position: absolute;
        padding-right: 0.25em;
        text-decoration: none;
      }
      #wrapperlicious h1:hover .permalink, #wrapperlicious h2:hover .permalink,
      #wrapperlicious h3:hover .permalink, #wrapperlicious h4:hover .permalink,
      #wrapperlicious dt:hover .permalink {
        display: block;
      }
    </style>
    <!-- Global site tag (gtag.js) - Google Analytics -->
    <script async src="https://www.googletagmanager.com/gtag/js?id=G-KVNWBNT5FB"></script>
    <script>
      window.dataLayer = window.dataLayer || [];
      function gtag(){dataLayer.push(arguments);}
      gtag('js', new Date());

      gtag('config', 'G-KVNWBNT5FB');
      gtag('config', 'UA-50555-3');
    </script>
  </head>
  <body>
    <nav class="navbar navbar-expand-md navbar-dark bg-dark justify-content-between">
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="https://perldoc.perl.org/">Perldoc Browser</a>
  <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="./CPAN::Meta::Merge.html#" id="dropdownlink-stable" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">5.35.0</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-stable">
          <a class="dropdown-item" href="https://perldoc.perl.org/CPAN::Meta::Merge">Latest</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.2/CPAN::Meta::Merge">5.38.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.1/CPAN::Meta::Merge">5.38.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0/CPAN::Meta::Merge">5.38.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.3/CPAN::Meta::Merge">5.36.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.2/CPAN::Meta::Merge">5.36.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.1/CPAN::Meta::Merge">5.36.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.36.0/CPAN::Meta::Merge">5.36.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.3/CPAN::Meta::Merge">5.34.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.2/CPAN::Meta::Merge">5.34.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.1/CPAN::Meta::Merge">5.34.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.34.0/CPAN::Meta::Merge">5.34.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.32.1/CPAN::Meta::Merge">5.32.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.32.0/CPAN::Meta::Merge">5.32.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.3/CPAN::Meta::Merge">5.30.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.2/CPAN::Meta::Merge">5.30.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.1/CPAN::Meta::Merge">5.30.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.30.0/CPAN::Meta::Merge">5.30.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.3/CPAN::Meta::Merge">5.28.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.2/CPAN::Meta::Merge">5.28.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.1/CPAN::Meta::Merge">5.28.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.28.0/CPAN::Meta::Merge">5.28.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.3/CPAN::Meta::Merge">5.26.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.2/CPAN::Meta::Merge">5.26.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.1/CPAN::Meta::Merge">5.26.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.26.0/CPAN::Meta::Merge">5.26.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.4/CPAN::Meta::Merge">5.24.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.3/CPAN::Meta::Merge">5.24.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.2/CPAN::Meta::Merge">5.24.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.1/CPAN::Meta::Merge">5.24.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.24.0/CPAN::Meta::Merge">5.24.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.4/CPAN::Meta::Merge">5.22.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.3/CPAN::Meta::Merge">5.22.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.2/CPAN::Meta::Merge">5.22.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.1/CPAN::Meta::Merge">5.22.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.22.0/CPAN::Meta::Merge">5.22.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.3/CPAN::Meta::Merge">5.20.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.2/CPAN::Meta::Merge">5.20.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.1/CPAN::Meta::Merge">5.20.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.20.0/CPAN::Meta::Merge">5.20.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.4/CPAN::Meta::Merge">5.18.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.3/CPAN::Meta::Merge">5.18.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.2/CPAN::Meta::Merge">5.18.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.1/CPAN::Meta::Merge">5.18.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.18.0/CPAN::Meta::Merge">5.18.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.3/CPAN::Meta::Merge">5.16.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.2/CPAN::Meta::Merge">5.16.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.1/CPAN::Meta::Merge">5.16.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.16.0/CPAN::Meta::Merge">5.16.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.4/CPAN::Meta::Merge">5.14.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.3/CPAN::Meta::Merge">5.14.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.2/CPAN::Meta::Merge">5.14.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.1/CPAN::Meta::Merge">5.14.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.14.0/CPAN::Meta::Merge">5.14.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.5/CPAN::Meta::Merge">5.12.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.4/CPAN::Meta::Merge">5.12.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.3/CPAN::Meta::Merge">5.12.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.2/CPAN::Meta::Merge">5.12.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.1/CPAN::Meta::Merge">5.12.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.12.0/CPAN::Meta::Merge">5.12.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.10.1/CPAN::Meta::Merge">5.10.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.10.0/CPAN::Meta::Merge">5.10.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.9/CPAN::Meta::Merge">5.8.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.8/CPAN::Meta::Merge">5.8.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.7/CPAN::Meta::Merge">5.8.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.6/CPAN::Meta::Merge">5.8.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.5/CPAN::Meta::Merge">5.8.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.4/CPAN::Meta::Merge">5.8.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.3/CPAN::Meta::Merge">5.8.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.2/CPAN::Meta::Merge">5.8.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.1/CPAN::Meta::Merge">5.8.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.8.0/CPAN::Meta::Merge">5.8.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.2/CPAN::Meta::Merge">5.6.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.1/CPAN::Meta::Merge">5.6.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.6.0/CPAN::Meta::Merge">5.6.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_04/CPAN::Meta::Merge">5.005_04</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_03/CPAN::Meta::Merge">5.005_03</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_02/CPAN::Meta::Merge">5.005_02</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005_01/CPAN::Meta::Merge">5.005_01</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.005/CPAN::Meta::Merge">5.005</a>
        </div>
      </li>
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="./CPAN::Meta::Merge.html#" id="dropdownlink-dev" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dev</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-dev">
          <a class="dropdown-item" href="https://perldoc.perl.org/blead/CPAN::Meta::Merge">blead</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.6/CPAN::Meta::Merge">5.39.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.5/CPAN::Meta::Merge">5.39.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.4/CPAN::Meta::Merge">5.39.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.3/CPAN::Meta::Merge">5.39.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.2/CPAN::Meta::Merge">5.39.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.39.1/CPAN::Meta::Merge">5.39.1</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0-RC2/CPAN::Meta::Merge">5.38.0-RC2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.38.0-RC1/CPAN::Meta::Merge">5.38.0-RC1</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.11/CPAN::Meta::Merge">5.37.11</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.10/CPAN::Meta::Merge">5.37.10</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.9/CPAN::Meta::Merge">5.37.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.8/CPAN::Meta::Merge">5.37.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.7/CPAN::Meta::Merge">5.37.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.6/CPAN::Meta::Merge">5.37.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.5/CPAN::Meta::Merge">5.37.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.4/CPAN::Meta::Merge">5.37.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.3/CPAN::Meta::Merge">5.37.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.2/CPAN::Meta::Merge">5.37.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.1/CPAN::Meta::Merge">5.37.1</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.37.0/CPAN::Meta::Merge">5.37.0</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.11/CPAN::Meta::Merge">5.35.11</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.10/CPAN::Meta::Merge">5.35.10</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.9/CPAN::Meta::Merge">5.35.9</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.8/CPAN::Meta::Merge">5.35.8</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.7/CPAN::Meta::Merge">5.35.7</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.6/CPAN::Meta::Merge">5.35.6</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.5/CPAN::Meta::Merge">5.35.5</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.4/CPAN::Meta::Merge">5.35.4</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.3/CPAN::Meta::Merge">5.35.3</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.2/CPAN::Meta::Merge">5.35.2</a>
          <a class="dropdown-item" href="https://perldoc.perl.org/5.35.1/CPAN::Meta::Merge">5.35.1</a>
          <a class="dropdown-item active" href="./CPAN::Meta::Merge.html">5.35.0</a>
        </div>
      </li>
      <li class="nav-item dropdown text-nowrap">
        <a class="nav-link dropdown-toggle" href="./CPAN::Meta::Merge.html#" id="dropdownlink-nav" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Documentation</a>
        <div class="dropdown-menu" aria-labelledby="dropdownlink-nav">
          <a class="dropdown-item" href="perl.html">Perl</a>
          <a class="dropdown-item" href="perlintro.html">Intro</a>
          <a class="dropdown-item" href="perl.html#Tutorials">Tutorials</a>
          <a class="dropdown-item" href="perlfaq.html">FAQs</a>
          <a class="dropdown-item" href="perl.html#Reference-Manual">Reference</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="perlop.html">Operators</a>
          <a class="dropdown-item" href="functions.html">Functions</a>
          <a class="dropdown-item" href="variables.html">Variables</a>
          <a class="dropdown-item" href="modules.html">Modules</a>
          <a class="dropdown-item" href="perlutil.html">Utilities</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="perlcommunity.html">Community</a>
          <a class="dropdown-item" href="perlhist.html">History</a>
        </div>
      </li>
    </ul>
    <ul class="navbar-nav">
      <script>
        function set_expand (expand) {
          var perldocdiv = document.getElementById('perldocdiv');
          var width = window.getComputedStyle(perldocdiv).getPropertyValue('max-width');
          var expanded = (width == '' || width == 'none') ? true : false;
          if (expand === null) {
            expand = !expanded;
          }
          if ((expand && !expanded) || (!expand && expanded)) {
            perldocdiv.style.setProperty('max-width', expand ? 'none' : '960px');
            var button_classlist = document.getElementById('content-expand-button').classList;
            if (expand) {
              button_classlist.add('btn-light');
              button_classlist.remove('btn-outline-light');
            } else {
              button_classlist.add('btn-outline-light');
              button_classlist.remove('btn-light');
            }
          }
          return expand;
        }
        function toggle_expand () {
          var expand = set_expand(null);
          document.cookie = 'perldoc_expand=' + (expand ? 1 : 0) + '; path=/; expires=Tue, 19 Jan 2038 03:14:07 UTC';
        }
        function read_expand () {
          return document.cookie.split(';').some(function (item) { return item.indexOf('perldoc_expand=1') >= 0 });
        }
        if (document.readyState === 'loading') {
          document.addEventListener('DOMContentLoaded', function () {
            if (read_expand()) {
              set_expand(true);
            }
          });
        } else if (read_expand()) {
          set_expand(true);
        }
      </script>
      <button id="content-expand-button" type="button" class="btn btn-outline-light d-none d-lg-inline-block mr-2" onclick="toggle_expand()">Expand</button>
    <ul>
    <form class="form-inline" method="get" action="https://perldoc.perl.org/5.35.0/search">
      <input class="form-control mr-3" type="search" name="q" placeholder="Search" aria-label="Search">
    </form>
  </div>
</nav>

    <div id="wrapperlicious" class="container-fluid">
      <div id="perldocdiv">
        <div id="links">
          <a href="./CPAN::Meta::Merge.html">CPAN::Meta::Merge</a>
          <div id="more">
            (<a href="./CPAN::Meta::Merge.txt">source</a>,
            <a href="https://metacpan.org/pod/CPAN::Meta::Merge">CPAN</a>)
          </div>
            <div id="moduleversion">version 2.150010</div>
        </div>
        <div class="leading-notice">
          You are viewing the version of this documentation from Perl 5.35.0.
            This is a development version of Perl.
        </div>
        <h1><a id="toc">CONTENTS</a></h1>
                  <ul>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#NAME">NAME</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#VERSION">VERSION</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#SYNOPSIS">SYNOPSIS</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#DESCRIPTION">DESCRIPTION</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#METHODS">METHODS</a>
                            <ul>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#new">new</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#merge(@fragments)">merge(@fragments)</a>
              </li>
          </ul>

              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#MERGE-STRATEGIES">MERGE STRATEGIES</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#AUTHORS">AUTHORS</a>
              </li>
              <li>
                <a class="text-decoration-none" href="./CPAN::Meta::Merge.html#COPYRIGHT-AND-LICENSE">COPYRIGHT AND LICENSE</a>
              </li>
          </ul>

      <h1 id="NAME"><a class="permalink" href="./CPAN::Meta::Merge.html#NAME">#</a>NAME</h1>

<p>CPAN::Meta::Merge - Merging CPAN Meta fragments</p>

<h1 id="VERSION"><a class="permalink" href="./CPAN::Meta::Merge.html#VERSION">#</a>VERSION</h1>

<p>version 2.150010</p>

<h1 id="SYNOPSIS"><a class="permalink" href="./CPAN::Meta::Merge.html#SYNOPSIS">#</a>SYNOPSIS</h1>

<pre><code>my $merger = CPAN::Meta::Merge-&gt;new(default_version =&gt; &quot;2&quot;);
my $meta = $merger-&gt;merge($base, @additional);</code></pre>

<h1 id="DESCRIPTION"><a class="permalink" href="./CPAN::Meta::Merge.html#DESCRIPTION">#</a>DESCRIPTION</h1>

<h1 id="METHODS"><a class="permalink" href="./CPAN::Meta::Merge.html#METHODS">#</a>METHODS</h1>

<h2 id="new"><a class="permalink" href="./CPAN::Meta::Merge.html#new">#</a>new</h2>

<p>This creates a CPAN::Meta::Merge object. It takes one mandatory named argument, <code>version</code>, declaring the version of the meta-spec that must be used for the merge. It can optionally take an <code>extra_mappings</code> argument that allows one to add additional merging functions for specific elements.</p>

<p>The <code>extra_mappings</code> arguments takes a hash ref with the same type of structure as described in <a href="./CPAN::Meta::Spec.html">CPAN::Meta::Spec</a>, except with its values as one of the <a href="./CPAN::Meta::Merge.html#MERGE-STRATEGIES">defined merge strategies</a> or a code ref to a merging function.</p>

<pre><code>my $merger = CPAN::Meta::Merge-&gt;new(
    default_version =&gt; &#39;2&#39;,
    extra_mappings =&gt; {
        &#39;optional_features&#39; =&gt; \&amp;custom_merge_function,
        &#39;x_custom&#39; =&gt; &#39;set_addition&#39;,
        &#39;x_meta_meta&#39; =&gt; {
            name =&gt; &#39;identical&#39;,
            tags =&gt; &#39;set_addition&#39;,
        }
    }
);</code></pre>

<h2 id="merge(@fragments)"><a class="permalink" href="./CPAN::Meta::Merge.html#merge(@fragments)">#</a><a id="merge"></a><a id="merge-fragments"></a>merge(@fragments)</h2>

<p>Merge all <code>@fragments</code> together. It will accept both CPAN::Meta objects and (possibly incomplete) hashrefs of metadata.</p>

<h1 id="MERGE-STRATEGIES"><a class="permalink" href="./CPAN::Meta::Merge.html#MERGE-STRATEGIES">#</a><a id="MERGE"></a>MERGE STRATEGIES</h1>

<p><code>merge</code> uses various strategies to combine different elements of the CPAN::Meta objects. The following strategies can be used with the extra_mappings argument of <code>new</code>:</p>

<dl>

<dt id="identical"><a class="permalink" href="./CPAN::Meta::Merge.html#identical">#</a>identical</dt>
<dd>

<p>The elements must be identical</p>

</dd>
<dt id="set_addition"><a class="permalink" href="./CPAN::Meta::Merge.html#set_addition">#</a>set_addition</dt>
<dd>

<p>The union of two array refs</p>

<pre><code class="plaintext">[ a, b ] U [ a, c]  = [ a, b, c ]</code></pre>

</dd>
<dt id="uniq_map"><a class="permalink" href="./CPAN::Meta::Merge.html#uniq_map">#</a>uniq_map</dt>
<dd>

<p>Key value pairs from the right hash are merged to the left hash. Key collisions are only allowed if their values are the same. This merge function will recurse into nested hash refs following the same merge rules.</p>

</dd>
<dt id="improvise"><a class="permalink" href="./CPAN::Meta::Merge.html#improvise">#</a>improvise</dt>
<dd>

<p>This merge strategy will try to pick the appropriate predefined strategy based on what element type. Array refs will try to use the <code>set_addition</code> strategy, Hash refs will try to use the <code>uniq_map</code> strategy, and everything else will try the <code>identical</code> strategy.</p>

</dd>
</dl>

<h1 id="AUTHORS"><a class="permalink" href="./CPAN::Meta::Merge.html#AUTHORS">#</a>AUTHORS</h1>

<ul>

<li><p>David Golden &lt;dagolden@cpan.org&gt;</p>

</li>
<li><p>Ricardo Signes &lt;rjbs@cpan.org&gt;</p>

</li>
<li><p>Adam Kennedy &lt;adamk@cpan.org&gt;</p>

</li>
</ul>

<h1 id="COPYRIGHT-AND-LICENSE"><a class="permalink" href="./CPAN::Meta::Merge.html#COPYRIGHT-AND-LICENSE">#</a><a id="COPYRIGHT"></a>COPYRIGHT AND LICENSE</h1>

<p>This software is copyright (c) 2010 by David Golden, Ricardo Signes, Adam Kennedy and Contributors.</p>

<p>This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.</p>


      </div>
      <div id="footer">
        <p>Perldoc Browser is maintained by Dan Book (<a href="https://metacpan.org/author/DBOOK">DBOOK</a>). Please contact him via the <a href="https://github.com/Grinnz/perldoc-browser/issues">GitHub issue tracker</a> or <a href="mailto:dbook@cpan.org">email</a> regarding any issues with the site itself, search, or rendering of documentation.</p>

<p>The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via the <a href="https://github.com/Perl/perl5/issues">Perl issue tracker</a>, the <a href="https://lists.perl.org/list/perl5-porters.html">mailing list</a>, or <a href="https://kiwiirc.com/client/irc.perl.org/p5p">IRC</a> to report any issues with the contents or format of the documentation.</p>


      </div>
    </div>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.slim.min.js" integrity="sha512-/DXTXr6nQodMUiq+IUJYCt2PPOUjrHJ9wFrqpJ3XkgPNOZVfMok7cRw6CSxyCQxXn6ozlESsSh1/sMCTF1rL/g==" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.1/umd/popper.min.js" integrity="sha512-ubuT8Z88WxezgSqf3RLuNi5lmjstiJcyezx34yIU2gAHonIi27Na7atqzUZCOoY4CExaoFumzOsFQ2Ch+I/HCw==" crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>
    <script src="../highlight.pack.js"></script>
    <script>hljs.highlightAll();</script>
  </body>
</html>
